While Western drivers like the “new car” smell fresh off the production line, Chinese would rather their cars didn’t smell of anything — a cultural divide that’s testing carmakers seeking an edge to revive sales in the world’s biggest auto market.

At Ford Motor Co., for example, 18 smell assessors, dubbed “golden noses,” at its research plant outside the eastern city of Nanjing test the smell of each material that goes inside a Ford car to be sold in China and around Asia.